中文摘要：

利用光学显微镜、X射线衍射仪和透射电镜研究了TC4合金氢处理后的微观组织变化,通过硬度测试分析了氢处理对TC4合金硬度的影响。结果表明,随着置氢量的增加,置氢后的TC4合金中出现了马氏体α′和氢化物δ,但除氢后的试样中只有α和β两相。TC4合金经过置氢再除氢后,微观组织细化,这是由于除氢时相互平行的共析产物（δ＋α）发生了相变和马氏体发生了分解。随着置氢量的增加,除氢后TC4合金的硬度增加,这是TC4合金微观组织细化的结果。

英文摘要：

Microstructure variation of TC4 alloy after hydrogen treatment was investigated by optical microscope （OM）, X-ray diffraction （XRD） and transmission electron microscope （TEM）. Effects of hydrogen content on hardness of TC4 alloy were researched by hardness testing. The results show that martensite α′ and hydride δ appear in the TC4 alloy after hydrogenation treatment with increase of hydrogen content, while only α and β phase existed in the alloy after dehydrogenation. Microstructure is refined in the alloy after hydrogenation and dehydrogenation treatment, which is attributed to the transformation of eutectoid （δ＋α）, in which the δ phase parallel to the α phase, and the decomposition of martensite α′. Hardness of the TC4 alloy is increased with the increase of hydrogen content after hydrogenation treatment as a result of microstructure refinement in the alloy.